1. Field of the Invention
The present invention relates to a digital television broadcasting signal receiver to receive digital television broadcast signals, such as ATSC (Advanced Television Systems Committee).
2. Description of the Related Art
Since, in North America where the ATSC digital television broadcast (TV broadcast) is provided, large cities are located in plain fields, and TV broadcast signals come from various directions from the viewpoint of users who receive TV broadcast signals sent from around each city, users need to adjust the direction of antennas towards the broadcast station which broadcasts programs they wish to watch. Therefore, a multi-directional antenna is coming into practical use.
According to the EIA-909 specification, a smart antenna is defined to have receiving directions in each of 16 directions into which a circle is divided. Meanwhile, as a digital television broadcast signal receiver that receives TV broadcast signals, it is set to be adjustable for the receiving direction of a multi-directional antenna for all 16 directions in order to comply with the EIA-909 specification.
On the other hand, there are some digital television broadcast signal receivers (digital TV broadcast signal receiver) that are equipped with an auto-scan function to select the antenna direction that can best receive TV broadcast signals of channels selected by a user.
In addition, the following methods are known: a method of watching programs via digital broadcast in good condition by switching transmission gains of a boot circuit for digital broadcast waves that are input to a tuner, even in the case of mixture of the digital broadcast and the existing broadcast with analog signals (see Japanese Unexamined Patent Application Publication 2003-274312); a method of making reception conditions better in ground wave digital broadcast receivers by calculating BER (BIT ERROR RATE) values with a decoder for digital broadcast signals as needed and controlling the existence of an antenna amplifier with the value (see Japanese Unexamined Patent Application Publication 2003-101428); and a method of performing actions, such as the frequency seek action, with AGC judgment values which are automatically adjusted by AGC voltage values based on the broadcast receiver specific reception limit BER, with the controlling of transmission gains of a tuner with AGC (see Japanese Unexamined Patent Application Publication 2003-101426).